Fatigue Behavior Characteristics of Hybrid Composites with Nonwoven Carbon Tissue

Abstract

Fatigue behavior characteristics of hybrid composites with nonwoven carbon tissue (NWCT) are investigated under tension–tension cyclic loadings. The hybrid composites were made by stacking NWCT-prepreg and CFRP-prepreg. To investigate the fatigue effects of the NWCT stacking, ten kinds of laminates were studied; i.e., NWCT composites, CFRP transverse [90]12, off-axis[45] 12 and angle-ply [±45]3S, hybrid transverse ([90//90//90//90//90//90/]S, [//90//90//90//90//90/]S), off-axis([45//45//45//45//45//45/] S, [//45//45//45//45//45//45/]S) and angle-ply ([+45//−45//+45//−45//+45//−45]S,[//+45//−45//+45//−45//+45//−45]S). The symbol “//” meansthat the NWCT-prepreg islocated between the CFRP layers. The effects of NWCT on the tension–tension fatigue life, the residual strength and stiffness of angle-ply hybrid specimens were evaluated after fatigue tests. The fatigue behaviorsof the hybrid compositeswere dependent on that of the NWCT composites. The fracture surfaces of the hybrid specimens and the fracture process on the side-edge section were observed with an optical microscope, and the failure mechanism was analyzed.